Charging a quantum spin network with superextensive precision

Year: 2025

Authors: Donelli B., Gherardini S., Marino R., Campaioli F., Buffoni L.

Autors Affiliation: CNR, Ist Nazl Ott, Largo Enr Fermi 6, I-50125 Florence, Italy; Univ Firenze, European Lab Nonlinear Spect, I-50019 Sesto Fiorentino, Italy; Univ Florence, Dept Phys & Astron, I-50019 Sesto Fiorentino, Italy; RMIT Univ, Sch Sci, Dept Phys, Melbourne, Vic, Australia; Univ Padua, Dipartimento Fis & Astron G Galilei, I-35131 Padua, Italy; Univ Padua, Padua Quantum Technol Res Ctr, I-35131 Padua, Italy; INFN, Sez Padova, Via Marzolo 8, I-35131 Padua, Italy.

Abstract: We present a cooperative protocol to charge quantum spin networks up to the highest-energy configuration, in terms of the network’s magnetization. The charging protocol leverages spin-spin interactions and the crossing of a phase transition’s critical point to achieve superextensive charging precision. The cooperative protocol guarantees a precision advantage over any local charging protocol and leads to fluctuations (standard deviation) of the magnetization that scale as 1/N, with N the number of spins in the network, i.e., the size of the spin battery. We test our protocol on the D-Wave Advantage quantum processing unit by charging sublattices with sizes ranging from 40 to 5612 spins, achieving the highest-energy configuration with a sizable superextensive charging precision scaling and outperforming the local charging precision by four orders of magnitude.

Journal/Review: PHYSICAL REVIEW E

Volume: 111 (6)      Pages from: L062102-1  to: L062102-7

More Information: B.D. and S.G. acknowledge financial support from the PNRR Ministry of University and Research (MUR) Project No. PE0000023, NQSTI, funded by Next Generation EU (NGEU) . S.G. also acknowledges support from the PRIN Project No. 2022FEXLYB Quantum Reservoir Computing. R.M. was supported by NGEU and funded by the MUR, National Recovery and Resilience Plan, project MNESYS (Project No. PE0000006) , A multiscale integrated approach to the study of the nervous system in health and disease (Grant No. DN. 1553 11.10.2022) . L.B. was funded by PNRR MUR Project No. SOE0000098, ThermoQT, financed by NGEU.
KeyWords: accuracy; article; controlled study; delta rhythm; phase transition
DOI: 10.1103/lffq-ylgz